<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>

  <div id="app">
    <h1>{{message}}</h1>
    <h2>{{count}}</h2>
    <button @click="add">++++</button>
  </div>
  <!-- 引入vue文件 -->
  <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js">

  </script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        message: 'hello Vue',
        count: 0
      },
      methods: {
        add() {
          this.count++
        }
      }
    });

    // const count = 0;
    // btn.onclick = function () {
    //   count++
    //   h2.innerHTML = count;
    // }
  </script>
</body>

</html>